LCP (30% Glass-Filled) vs PEEK
LCP (30% glass-filled) and PEEK are both elite high-temperature engineering plastics, but they excel differently. Glass-filled LCP offers exceptional melt flow for thin-wall molding, very low and isotropic-controlled shrinkage, low CTE, and strong chemical resistance — ideal for tiny electronic connectors. PEEK is tougher, more wear-resistant, and handles higher temperature (~250 vs ~240 C), serving demanding mechanical, chemical, and medical parts.
The verdict
Choose LCP 30% glass-filled for thin-wall, high-precision molded parts like electronic connectors that need excellent flow, dimensional stability, and low CTE. Choose PEEK for tougher, wear-resistant, higher-temperature mechanical and medical components where impact resistance and longevity matter.
Side-by-side data
| Property | LCP (30% Glass-Filled) | PEEK |
|---|---|---|
| Category | Engineering Plastic | Engineering Plastic |
| Density (g/cm³) | 1.62 | 1.32 |
| Tensile strength (MPa) | 135 | 100 |
| Yield strength (MPa) | 135 | 97 |
| Elongation (%) | 2 | 45 |
| Hardness | R80 | R126 |
| Max service temp (°C) | 240 | 250 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 0.5 | 0.25 |
| Typically used for | Thin-wall electronic connectors | High-temp, chemical & medical-grade parts |
Which should you choose?
Choose LCP 30% Glass-Filled when…
- Thin-wall molding demands excellent melt flow — LCP fills tiny features other resins cannot
- Dimensional precision and low, predictable shrinkage are critical for connectors
- Low coefficient of thermal expansion is needed for solder/reflow stability
- The part is a small, high-density electronic connector (its best-fit use)
- Strong chemical resistance (5/5) at elevated temperature is required
- Cost is lower than PEEK (~4.0 vs ~5.0) at high volume
Choose PEEK when…
- Toughness and impact resistance matter — PEEK's elongation (~45%) far exceeds glass-filled LCP (~2%)
- Wear and friction performance drive part life in bearings and seals
- Higher service temperature is needed (~250 C vs LCP ~240 C)
- The part is medical-grade, chemical, or a demanding mechanical component
- Higher tensile strength is required (~100 vs LCP-GF ~135 MPa is glass-driven, but PEEK is far tougher unfilled)
- Machined parts are needed — PEEK machines from stock readily
Key differences that matter
- Both are high-temperature plastics; PEEK tolerates slightly more (~250 vs ~240 C)
- Glass-filled LCP's standout traits are exceptional melt flow, low/controlled shrinkage, and low CTE for thin-wall precision molding
- PEEK is far tougher and more impact-resistant (elongation ~45% vs LCP-GF ~2%) and more wear-resistant
- Glass-filled LCP shows higher tensile (~135 MPa) from the glass fill, but is brittle; unfilled PEEK is tougher
- Both are chemically resistant at 5/5 and serve harsh-environment roles
- LCP excels at tiny electronic connectors; PEEK excels at mechanical, wear, and medical parts
- PEEK is the more expensive (~5.0 vs ~4.0) but more versatile, machinable material
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Why is glass-filled LCP used for connectors?
LCP has exceptional melt flow, so it fills extremely thin walls and fine features that other high-temperature resins cannot, and it has very low, controlled mold shrinkage and a low coefficient of thermal expansion. That combination yields dimensionally precise, reflow-stable miniature electronic connectors — its signature application — where PEEK's flow and shrinkage are less ideal.
Which is tougher, LCP-GF or PEEK?
PEEK, by a wide margin. Glass-filled LCP is stiff and strong (~135 MPa tensile) but brittle, with elongation around 2%, so it cracks rather than deforms. PEEK has roughly 45% elongation, absorbing impact and resisting fatigue. For mechanical parts that see load, shock, or flexing, PEEK is far more durable.
Do both handle high temperature?
Yes. Glass-filled LCP serves to about 240 C and PEEK to about 250 C, both far above commodity plastics, with strong chemical resistance (5/5). PEEK has a marginally higher ceiling and better high-temperature toughness, while LCP's advantage at temperature is dimensional stability and low expansion rather than mechanical robustness.
Can PEEK be machined while LCP cannot?
PEEK is readily machined from stock shapes for one-off and low-volume parts, which is a major practical advantage. Glass-filled LCP is primarily an injection-molding material optimized for thin-wall, high-volume connectors; it can be machined (rated 2.5) but is abrasive and brittle. For machined components, PEEK is the more workable choice.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.